Damn! The forecast is getting worse. Movement north of Galveston will bring more rain and storm surge to NO. Plus, the storm stalling over TX/LA/AR means more water for the Mississippi, threatening those levees at NO.
"Beyond this cycling phase, the new GFS 12Z model run continues to show landfall further east - now along the
TX./LA border. This dramatically increases the potential storm surge threat for southwest LA, while reducing the threat to Galveston. Whether or not this is just a 'flip-flop' in the track evolution is simply unknowable -- but the initialization data shows the high pressure ridge to the north weakening as forecast by the GFS, and I'm
inclined to believe it. Accordingly, from my perspective, the highest probability; for landfall, lies from near High
Island, Texas (about midway between Galveston and Port Arthur) eastward to Cameron, LA. If landfall reaches
Port Arthur or a bit east - hurricane force winds will reach eastward to Grand Isle, LA. -- and the storm surge would
shift accordingly -- with a 7-10ft storm surge over to Grand Isle, and 5-8 feet across the Mississippi Delta.
Before accepting this further east scenario we will at least need to see all the 18Z model runs show this change,
and then confirm it with the evening, 00Z run. Special upper air surveillance missions are planned for the
evening model runs -- and this should add greatly to the accuracy of the track forecast.
Beyond the issue of the actual landfall point -- for the past 2 days, the global models have been forecasting the
re-development/intensification of the high pressure ridge over the central U.S. -- and then expands it towards the
Gulf coast. What this means, is that after Rita moves inland Saturday morning, it will gradually slow down, then
stall out over west central Louisiana - and then is forecast to drift SOUTHWESTWARD towards Houston by
Monday. This type of motion would lead to extreme rainfall totals across much of Louisiana and the east-
southeast areas of Texas following landfall. Tremendous, life threatening flooding could result from portions of
Louisiana southwestward to the Houston area. Storm rainfall totals could easily exceed 20" in some locations. |
